<div class="header">
    <h6 class="text">学生管理系统</h6>
    <div class="welcome">
        欢迎你，<h4 th:text="${username ?: '游客'}"></h4>
        <span style="color: #666; font-size: 12px; margin-right: 10px;">
            您是第<span th:text="${visitCount}">0</span>位访问用户
        </span>
        <img class="picture" width="50" height="50" th:src="@{/img/1.jpg}" />
        <a th:href="@{/logout.html}" class="out">退出</a>
    </div>
</div>